Micro electro mechanical systems devices such as fluid-ejecting devices are employed in various capacities including print cartridges. Many micro electro mechanical systems devices utilize substrates having slots formed therein. Slots can be formed utilizing various suitable substrate removal techniques. Different substrate removal techniques have different attributes such as substrate removal rates, slot shapes which can be formed with the technique, and controllability of the technique, among others. Improved slots and/or processing parameters can be achieved by utilizing a combination of substrate removal processing techniques to take advantage of these attributes.